It requires the following features: xslt-3.
The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:xslt version="3.0">
<p:with-input port="source">
<doc/>
</p:with-input>
<p:with-input port="stylesheet">
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="3.0">
<xsl:param name="var1" required="yes"/>
<xsl:param name="var2" required="yes"/>
<xsl:template match="/">
<result>
<xsl:value-of select="$var1"/>
<xsl:text> </xsl:text>
<xsl:value-of select="$var2"/>
</result>
</xsl:template>
</xsl:stylesheet>
</p:with-input>
<p:with-option name="parameters" select="map{'var1' : 'XProc', 'var2': 3}"/>
</p:xslt>
</p:declare-step>
Schematron validation
<s:schema xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:pattern>
<s:rule context="/">
<s:assert test="/result">The document root is not 'result'.</s:assert>
<s:assert test="/result/text()='XProc 3'">The text child is not 'XProc 3'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
